The following color filters have been used for various kinds of displays such as a liquid crystal display.
1. A color filter obtained by forming a polymer film superior in dyeability on a transparent substrate and then patterning the polymer film by photolithography followed by coloring.
2. A color filter obtained by forming a polymer film superior in dyeability on a transparent substrate and then drawing a color filter pattern with dye.
3. A color filter obtained by forming a pigmented polymer film pattern on a transparent substrate by photolithography.
4. A color filter obtained by forming a transparent electroconductive film pattern, e.g. an ITO film pattern, on a transparent substrate and then applying an electrodepositable paint on the transparent electroconductive film.
5. A color filter obtained by forming a colored polymer film on a transparent substrate by a printing method.
However, the above described color filters have the following disadvantages.
The color filter of the method 1 is poor in surface flatness and strength.
The color filter of the method 2 is superior in surface flatness, because the polymer film is not patterned but colored as a color pattern. The filter, however, is poor in surface strength, because it employs polymer material. Also, since the patterns of the respective colors are colored on the same one polymer film, bleeding and migration of the dyes occurs.
Since the color filter of the method 3 is obtained by coloring the polymer film on the transparent substrate in the same manner as the color filter 1, it is poor in surface flatness and surface strength. In addition, a problem may occur in that light is scattered by pigment particles.
In the production of the color filter of the method 4, the patterned transparent electroconductive film has to be formed, and it is further required in many cases that a transparent electrode from ITO and the like is formed on the electrodeposited coat, so that the producing process becomes complicated. In addition, since the electrodepositable paint is applied on the transparent film pattern, the obtained color filter is poor in surface flatness.
The color filter of the method 5 is also poor in surface strength, because it employs polymer material as mentioned in the method 1.
It is an object of the present invention to solve the above described problems and provide a method for efficiently producing a color filter superior in various kinds of physical properties.